It is known that the resistance of the resistance wire is about 10 ohm. The following equipment are available for measuring the resistance of the resistance wire. The equipment to be selected are________ A. Ammeter (0.6A 0.5ohm) B. Ammeter (3a 0.1 Ohm) C voltmeter (3V 6000 Ω) D voltmeter (15V 30000 Ω) E sliding rheostat (0 -- 5 Ω 1a) F sliding rheostat (0 -- 1000 Ω 0.5A) G battery 6V H key

A C E G H

To measure a resistance value of about hundreds of ohm, we need to measure a resistance value of about hundreds of Ohm in the laboratory
In the laboratory, we need to measure a resistance with a resistance value of about several hundred ohm. The equipment we can provide include: two dry batteries, voltmeter for students (the range is 0 ~ 3V, 0 ~ 15V), sliding rheostat (100 Ω 2a) and resistance box (0 ~ 9V)
999 Ω, 5a), switch and wire
Please write down the experimental scheme you designed (use the corresponding letters to indicate the measured physical quantities)
(1) Experimental ideas;
(2) Circuit diagram;
(3) Laboratory equipment;
(4) The procedure of the experiment;
Write the expression of resistance Rx to be measured

1. Test idea: & nbsp; & nbsp; because no ammeter is used, Ohm's law r = u / I cannot be used directly. However, voltage dividing circuit can be used to measure the voltage U1 on the known resistance R1 and the voltage U2 on the measured resistance Rx, then: & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; U2 / U1 = Rx / R1 & nbsp; that is & nbsp

What is the color of a 200 ohm resistor

Four color ring: red black brown gold five color ring: Red Black Black Brown

What's the color of a 22 ohm resistor

The first three rings of 4-color ring resistor are red and black, and the first four rings of 5-color ring resistor are red, red, black and gold

How to distinguish which consumer is the voltage transformer in the circuit diagram

First of all, we need to correct a saying that it is a voltmeter, not a voltmeter. This is easy to do. I have a way to absolutely work. That is to see the two nodes of the voltmeter. How to judge? Use the current flow method to let the current start from the positive pole of the power supply and reach a connection point of the voltmeter. After this connection point, and between the other connection points

Can the ammeter and electric appliance be interchanged?

If it's a series circuit, it can,
If it is a parallel circuit, it is generally not possible

How to distinguish between voltmeter and ammeter in circuit diagram?

The voltmeter is connected in parallel with both ends of the device under test, while the ammeter is connected in series with the device under test. As long as the current of the device in series with the ammeter is the value of the ammeter, and as long as it is connected in parallel with the voltmeter, the voltage applied at both ends is the reading of the voltmeter

How to distinguish the current or voltage measured by ammeter or voltmeter? Are there any tips?

The ammeter connected in series with that branch is the current of that branch. The two ends of the voltmeter connected in parallel with that electrical component is the voltage of that component
As shown in the figure, V1 and L1 are in parallel, and L1 voltage is measured. V2 and L2 are in parallel, and L2 voltage is measured. V3 and power supply are in parallel, and power supply voltage is measured

How to draw a circuit diagram when voltmeter and ammeter measure an electric appliance at the same time

Three phase motor delta connection. Power 15 kW. Voltage 380 v. what is the current?
The power factor is 0.9

First of all, is it possible for the power factor to be 0.9? No, but when the three-phase motor is connected in a triangle of 15kw, it is the rated current of the motor. Given the formula, the answer is also an approximate value, because it is related to the design, processing, materials and so on of the manufacturer, It is an approximate value. Formula: I ≈ P / √ 3 / U / cos ￠ / η followed by the working efficiency of the motor, which is generally 0.91-0.94. According to the advanced degree of motor materials and processing, the known number is set into the formula; I ≈ 15000 / √ 3 / 380 / 0.9/0.91 is about 28a, because the power factor is not so high, which is generally about 0.8, so the rated current is about 30A, You go to see the motor standard plate, the above rated current is how much? Therefore, we usually add motor current value judgment is 1kW / 2A